At a quick shut off of certain mixing valves of one lever type, in particular if the water pipes are of small dimension, it can arise a pressure chock that exposes the water work system for strong loads as well as causes noise.
Through for example SE-B-462 503 and SE-B-455 124 it is earlier known mixing valves, which are provided to build up a pressure in a provided part of the valve at a quick shut off of the valve lever, so that a certain damping resistance is obtained at the endphase of the lever, which requires added force and thereby extends the closing phase. This happens by the reason that the valve is equipped with a separate pressure chamber, that is filled up via a non-return valve when the valve opens. When closing the valve the water is pressed out from the pressure chamber through passages in the non-return valve, whereby too quick closing movements are slowed down.
These known so called soft closing mixing valves show the disadvantage that they feel inert even at a normal shut off compared to a mixer without the soft closing function. They are furthermore sensitive to impurities in the water, which may damage the parts included in the soft closing function. Moreover the whole valve begins to leak if a leakage arise in the soft closing function.